Alternating-current dynamo-electric machine.



D. G. JACKSON. ALTERNATING GURRENT DYNAMO ELEGTRIG MACHINE. APPLIIGATIONFILED FEB. 23, 1904.

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Patented June 15.1909.

D. 0. JACKSON. ALTERNATING CURRENT D-YNAMO ELECTRIC! MACHINE. vAPPLIOATION FILEDVIER-ZS, 1804. 924,99 1 Patented-June 15, 1909.

2 SHEETS-SHEET 2 5 from the armature winding to the commuranged to beoperated as a motor.

PATENT OFFICE.

DUGALD O. JACKSON, OF MADISON, WISCONSIN.

ALTEBNATING-GURREHT DYNAMO-ELECTBIO meme.

Specification of Letters, Patent.

Patented June 1.5, 1909 Application filed nebmary 23, 19414. Serial no.194,722.

To allwh-cm it may concern:

Be .it known that I, DUGALD C. JACKSON, citizen of the UnitedStates,residing at Madison, in the county of Dane and State of W isconsin, haveinvented a certain new and useful Improvement in Alternating-Qurrent D.amo-Electric Machines, of which the to lowing is a full, clear, concise,and exact description, reference being had to the accompanying'drawings,forming a part of this specification.

. My invention relates to dynamo electric machines,'and moreparticularly to variable speed alternating current motors, and has forits object'impro'ved means for centrolling,

such machines and for more accurately var the" s eed thereof whileinjurious spar g at t e brushes is at the same time prevented. p y Inmyco-pending application, Serial No. 188,485 filed Januar 1-1, 1904, Ihave shown a motor of which t e armature is provided witha winding andcommutator, with resistances interposed in conductors leading tator andother resistances bridged between suitable'points on the winding orcommutator. v

The main object of my resent invention to provide-additional an improvedcircuit connections. for a machine with an armature is thisconstruction, which will enable the machine to. be more readilycontrolled and by which its speed when used as a motor can be moreaccurately governed.

Figure 1 is a diagrammatic view showing one arrangement, the motorcircuits being directly' connected with the supply circuit.

Fig. 2 shows a modified arrangement, the motor circuits beinginductively connected with the su ply circuit. Fig. 3 shows another mod'cation, the motor being connected with the supply circuit throughautotransformer mechanism, and Fig. 4 shows another modlfication, themotor being connected with the supply circuit through transformermechanism; of modified arrangement.

In'Fig. 1- of the accompanying drawing I have shown a machine such as isdescribed in he referred to co-pendiug application ar- It condiets of afield ring 1, provided with a field The armature core 3 is provided witha continuous winding 4 connected by means of leads 5, 5 to segments 6, 6of the commutator 7. The armature may also be provided with a shortcircuited winding '8 which may be of the squirrel-cage type. I haveshown brushes 9, con'nected inseries with the field winding'2,, whichbrushes may be placed in or near the' normal neutral line. A variableresistance or impedance -10 ma be adapted for serialinclusion in circuitwit the brushes 9 and the field winding, and a variable impedance orresistance 11 may be brid ed across the armature terminals 12, 13, as sown or this may be re laced by an autotransformer 11 or equiva entdevice by means of which the voltage impressed on the armature terminalsmay be varied as dei'sired as shown in Fig. 3. By means of thecontrollers 10 and 11 the current flow throu h the field and brushes 9may be con.- trolle and the speed of the motor regulated. I also providean additional set of brushes 14, 14 which may enga e the commutator.

at a point oh the norina neutral line, these brushes being included inan inde endent local circuit 15', which also may inc ude variableresistance or impedance 16. By

vent abnormal current flow. through the.

leads 5, 5 from any armature coil which otherwise would practically beshort cire cuited each time a brush bridges adjacent segments, 1 show aresistance 18 in each lead, whereby theabnormal current flow through thearmature coils and'leads is prevented. -In the circuit connections shownm Fig. 1,

which br ng the field and armature winding into series relation, theconductors-19 and 20 leading to the motor are connected directly to themain conductors of the alternating current circuit 21 which is suppliedwith current from a source 22.

In Fig. 2 I have illustrated a modified a1- rangement of connections inwhich the field and armature are connected in independent ingsrespectively in branches 2 3 and 24 from -the main circuit) may beincluded respectively in said circuits. Variableimpedance or resistance27 of appropriate quality is adapted for inclusion 1n the secondarycircuit 28, including the brushes 9, 9, and variable resistance orimpedance 29 may be 1ncluded in the secondary circuit 30 which in'cludes the field winding 2 of the motor. The transformers 25 and 26 neednot be of equal ratios of transformation but should be properly adaptedto the characters of the windings used on the motor. Transformer 25 andcontroller 27 .may be replaced by an autotransformer 25" or equivalentdevice for varying the voltage impressed on the armature withinappropriate limits as shown in Fig. 4. As in the arrangement shown 'inFig. 1, I here also-connect additional brushes 14, 14 in a local circuit15, which is independent fromthe external main circuit. Avariabl'e'resistance or impedance of appropriate quality- 16 is adaptedfor inclusion in said circuit for purposes of regulation. In thismodification as depicted, the short circuited winding is not employed,the operation of the motor being entirely dependent upon the reactiondue to the commutated winding which, if the resistances 17, 17 bridgingbetween the armature leads are suitably chosen with that in view, mayact to give the joint effect -ofa commutated winding and a shortcircuited winding.

By means of the arrangements of the brushes and circuits as described,the speed and torque of the motor may be very accurately controlled,thus causing the motor to be well adapted for the propulsion andoperation of electric vehicles.

I do not wish to be limited to the exact and precise arrangements shown,as modifications may readily be made without departgting from the. scopeof the invention,

u Having described my invention, I claim as new and desire to secure byLetters Patent:

1. In combination, a field magnet connected with a source of alternatingcurrent,

an associated armature core, a commutated winding on said core, acommutator connected by suitable leads with said commutated winding, aset of brushes bearingon' said com'mutator'and connected to receivecurrent from said sourceof alternating current, a secondary set ofbrushes bearing on said commutator, a local circuit connecting thebrushes'of the secondary set, and resist-J ancespartiallyshort-circuitingsaid commutated winding. I

2. In combination, a field magnet connected with a'source of alternatingcurrent,

an associated armature core, a commutated winding on said core, acommutator connected by suitable leads with said commutated winding,aset of brushes bearing on said commutator and connected to receivecurrent from said source of alternating current, a secondary set ofbrushes bearing on said commutator, a-local circuit connecting the.brushes of said secondary set, and conductors-of highrion-inductiveresistance connected in bridge of said leads.

3. In combination, a field magnet, an autotransformer connected inseries with said field magnet to. a source of alternating current, anarmature having a commutated winding and a closed circuited Windingassociated with said field magnet, a commutator connected by suitableleads with said commutated winding, a set of brushes bearing on circuitconnecting the brushes of said sec- 'ondary set, resistances seriallyincluded in the leads connecting the commutator with the commutatedwinding, and resistances partially short-circuiting .said commutatedwinding.

- 4. In combination, a field magnet, an autotransformer connected inseries with said field magnet to a source of alternating current, anarmature having a commutated winding, a commutator connected by suitableleads with said commutated winding, a set of brushes bearing on saidcommutator and deriving current from said autotransformer, a secondaryset of brushes bearing on said commutator, a local circuit connectingthe brushes of said secondary set, resistances serially included in theleads connecting the commutator with the commutated winding, andresistances partiallyshort-circuiting said'commutated winding! 1 5.Incombinatioma field magnet, an autotransformer connected in series withsaid field magnet .to a source of alternating current, an armaturehaving a commutated winding and a closed circuite-d winding associatedwith said field magnet, a commutator connected by suitable leads withsaid commutated Winding, a set of brushes bearing on said commutatorandderiving current from said auto-transformerfa secondary set of brushesbearing on said commutator, a local circuit connecting the brushes ofsaid -secondary' set, and resistances partially shortcircuiting saidcommutated] winding.

transformer. connected in series with said field magnet to-a source ofalternating current, an armature having a commutated winding, acommutator connected by suit-' able leads with said commutated Winding,a set ofibrushes bearing on said commutator and. deriving current fromsaid auto-trans- 6. In combination, a field magnet, an autoformer, asecondary set of brushesbea-r-ing-on said commutator, a'local eircult.connecting.

the brushes of said secondary set, and resistances partiallyjshort-c-irculting said commutated Winding-L 7. In combination, a sourceof alternating current, a motor having its field winding connected withsaid source, anauto-transformer connected inseries with said fieldWinding, an gassociated armature having a commutated winding connectedby suitable leads with a commutator, a set of brushes bearin on saidcommutator at or near the norma neutral-line and deriving current fromsaid auto-transformer, a secondary set of brushes hearing on saidcommutator at points rc moved from the 'normal neutral line, the"brushes of the secondary set being connected through an independentcircuit, means for controllingthe various circuits, resistances seriallyincluded in'said leads, and other resistances connected in bridge of theleads and serving partially to short circuit the coils of the commutatedarmature winding.

8. In'combinatioma source of-alternating current, a motor having itsfield Winding c0nnected with said source, an auto-transformer connectedin series with said field winding, an associated armature having acommutated winding connected bv suitable leads with a commutator, a setof brushes bearin on said commutator at or near the norma neutral lineand deriving current from said auto-transformer, a secondary set ofbrushes bearing on said commutator at points removed from the normalneutral line, the brushes of the secondary set being connected throughan independent circuit,

means for controlling the various circuits,"

and resistances connected in bridge of the leads and serving partiallyto short circuit thecoils of the commutated armature Winding.

In Witness whereof, I hereunto subscribe my name this sixteenth day ofFebruary DUGALD O. JACKSON.

WVitnesses:

WM. B.'JACKSON, DORA E. CASEY.

